Thread: Fine dust Problem??

Zelk,

Although we could do the math, it turns out my shop is just a bit bigger than yours and a big normal 120V AC exhaust fan in the doorway works great. I tried at first a little box fan then an oscillating fan but they proved underpowered.

Another alternative if you get more serious about spending lots of time in your shop and want better fine dust collection is building a cyclone of my design with a 14" diameter. That will fit under your short ceiling height and still give you plenty of airflow for good source collection. There are a few threads on this site from those who have built my cyclone design and seem pretty pleased at the performance.

bill

Originally Posted by bill pentz

Zelk,

Although we could do the math, it turns out my shop is just a bit bigger than yours and a big normal 120V AC exhaust fan in the doorway works great. I tried at first a little box fan then an oscillating fan but they proved underpowered.

Another alternative if you get more serious about spending lots of time in your shop and want better fine dust collection is building a cyclone of my design with a 14" diameter. That will fit under your short ceiling height and still give you plenty of airflow for good source collection. There are a few threads on this site from those who have built my cyclone design and seem pretty pleased at the performance.

bill

Bill,
At this stage its easier to fit a exhaust fan and it will be useful for removing fumes/odours from the workshop. I guess consideration must be made to where the fan is fitted in relation to where the fresh air is likely to enter the workshop and where I will be spending most of my time working. I would prefer to stand in the way of incoming fresh air.

Zelk

Originally Posted by reuelt

Thanks Mic,
I have a portable Carbon Monoxide meter because as I said earlier, I collapse because of CO in the field caused by 2-stroke lawn Mower.

And your point about the CO meter is???
I find it highly unlikely that you would get CO poisoning in the open air, to the point of collapse. The CO would be too dilute and there are more stages to CO poisoning such as headache, nausea, dizziness that would have incapacitated you first. And if you become unconscious from CO poisoning, you do not recover in a few seconds. It takes minutes to hours to blow off the CO. And if you think that a 4 stroke is going to produce much less CO than a 2 stroke, you're mistaken.

I do not now have a clean room nor do I think that is necessary. It is easy to make a clean gloved box if all I need is to measure some exhaust. One of the Bro. who attends our prayer meeting and stays 10 mins away, has sophisticated portable Gas & particle analyser but I still think we are off the objective.
No, the objective is you think you can make an improvement in dust collection, whether you do it for science, for money or for your family and your health, I thought you would want to know if it works. You do want to know if it works, for your family's sake don't you?

As I said, I was trying to copy the "Venturi Scrubber" Design. That design is reported to be even effective for sub-micron particles.
e.g. http://www.scielo.br/pdf/mr/v8n2/a16v8n2.pdf
No, you did not say. This is the first time you mentioned 'venturi'. As I have constantly been asking you, please explain how you will address the water consumption, and electricity consumption of this high energy scrubber. The researchers in the paper you linked to above specifically mention that a problem with them is the power required for their operation. And if you note carefully the graphs supplied, their test unit rates from about 95% efficient at 0.5 micron to 98% efficient at 2 micron. You can do this or better just with a dry filter system. And it use 900ml/min water!

I do not want to deviate from my objective. I am not going to write a scientific report.
If people want to question "wet scubbers", they should also question cyclones efficiency (see attached).

My background was chemical/biochemical engineering so of cause I do just not talk of "duct counts & dust sizes". I also had been a factory manager for 15 years.
And I have a PhD in chemistry, do you want to get into a pi**ing competition?
If a cyclone system drives a lot of air outdoor, CO & pollen dust are going to come in with the replacement air. These are toxic & irritants as well.
Are you seriously suggesting that the level of CO and pollen inside your house is any lower than the ambient levels?
Best regards.

Cheers
Michael

As the dust particles are heavier than air they will settle so it is best to have exhaust fans set low which will assist pulling the dust below the breathing zone.
I'd also consider an inlet fan above your work area.

This is the general basis of spray painting ventilation and I suggest there are sufficient behavorial similarities between supefine wood dust and paint spray mists for it to successfully work.

I would like to know more about how electrostatic charge on dust particles makes them float in the air, can you provide me with some references on this subject please?

CHeers
Michael

Originally Posted by reuelt

An exhaust fan or chimney would help if it is hot air. It may help to bring in air from the door or window.
But fine dust is a different problem. It is held in the air (floating) by electrostatic charges.
We need to catch them at the source.
I have stopped using my belt and palm sander. I now use the bend sender only to sharpen tools.
I have stopped using my lathe. Until I can find some way to capture the dust at source.
As Bill pointed 1000CFM suction draft hood may be required. But that is if you use only suction. 100% correct.
But haven't we forgotten something about "air curtains" principles. Air from top and suction at bottom? They use that for aircond and clean-rooms entrances.
That is what I am basically trying to do. Air-curtain for Sanding station, Air-curtains for lathe so that dust gets into the suction port.
If you think about it, a scoll sawler will benefit, a triton user could benefit - of course if and only if the air curtains jets are done properly.



Best regards.

If you illuminate a darkened workshop immediately after using a fine dust generator such as a drum sander or scrollsaw you can see the gust in the air when you turn on a light beam such as a torch. The light refects off the dust particles making them visible.
After a few minutes all the fines settle.

If they were electrostatically charged I expect they would float for a very long time instead of a few minutes,

But then again an electrostatically charged particle will only float by virtue of the charge if it is repelled by a similar charge. So that theory seems a bit cockeyed.

Hey guys good thread. Like it. Plenty of discussion and ideas.

I know its late and I'm a bit tired after reading the whole thread but I am now questioning my rough as guts set up.

I am working out of a 2 car garage. Double tilt a door front and a single roller door at the back with a sliding glass window beside that. Side door into house. Reasonable breeze half the time.

I have a generic 2 hp dusty and a rough cyclone(read leaking) feeding it.The cyclone extends the bag life of the dusty by about 10 times I would guess. I put the dusty outside when I am working. #1 the noise and #2 I know the dust rating is 10 micron at best. Needlefelt bag is nearly buggered. Going to upgrade soon to a pleated filter. To this I use a jointer, planer, band saw and table saw.

With my hand held power tools, I use a 1400w hoover vac with a modified triton (cyclone
) dust bucket. Router table and sander would be the usual suspects.

I wear a p2 disposable dust mask whenever I do any work. I would rather use one of these than a respirator as I find them uncomfortable, hot and generally a pita.

Is this good enough for a lay person? Or am I a bit light on? I know I do end up with a reasonable amount af shavings and dust on the floor and benches which I try to clean regularly.(Sorry Major but my shop doesnt look like yours)

I know there is a lot been said about cyclones and the like but is it feasable/better to run a couple of stages of cyclones before the dusty and also with the vac cleaner? With this I mean a coarse dusty then exhausting to a bank of say 3 smaller and then off to a vac cleaner. Or would I be better getting a good hepa filtered vac? Or both?

Shane.

Shane,

I’ve put a few comments in blue. Hope they help.

Bill

QUOTE=wattlewemake;887458]Hey…

I am working out of a 2 car garage. Double tilt a door front and a single roller door at the back with a sliding glass window beside that. This is pretty much the norm for most more serious hobbyists and believe it or not 6 out of 7 professional U.S. woodworkers (U.S. 2000 census data). Side door into house. Reasonable breeze half the time. Most don't have a breeze, so they need a fan in the side door running when they work wood even with hand tools. You can get by as long as you have a pretty good breeze and all doors open, but when you don't you should also use a good exhaust fan blowing out the side or back door with the main doors cracked. You also should wear a good dual cartridge dust mask when making fine dust as your 2 hp unit just does not move enough air to be a good fine dust collector and most tool hoods let the tool blow the fine invisible dust all over. Remember it is the fine invisible dust sized 10-microns and smaller which does the most health damage. This stuff is invisible without magnification and tends to build to dangerously high amounts in enclosed shops, then just about any activity including walking around launches this stuff airborne again and again. This dust also remains airborne in typical interior airflows. Contrary to what some think, what keeps this dust airborne are normal room air currents and Brownian motion http://en.wikipedia.org/wiki/Brownian_motion meaning random bumps from the air molecules.

I have a generic 2 hp dusty and a rough cyclone (read leaking) feeding it. Another good reason to wear a good mask while making fine dust. The cyclone extends the bag life of the dusty by about 10 times I would guess. That is about right, but remember that unless you have an air quality meter such as the Dylos http://www.dylosproducts.com/ you can't tell when a finer filter has bit the dust and no longer filters off the fine invisible particles. I put the dusty outside when I am working. #1 the noise and #2 I know the dust rating is 10 micron at best. Outside, preferably with a fire barrier is the best place for dust collectors and cyclones .Needled felt bag is nearly buggered. Going to upgrade soon to a pleated filter. The pleated filters may or may not be a good idea as they tend to be expensive and as long as you can put the DC outside and you either use the fan or have stiff breeze you don't need one. To this I use a jointer, planer, band saw and table saw.

With my hand held power tools, I use a 1400w hoover vac with a modified triton (cyclone
) dust bucket. Router table and sander would be the usual suspects. Both are a pain to control the dust and chips they generate, but there are some fairly good hood solutions on my Ducting web page.

I wear a p2 disposable dust mask whenever I do any work. I would rather use one of these than a respirator as I find them uncomfortable, hot and generally a pita. I agree about the discomfort, but unless you have an airtight seal on your P2 mask, it does not do a very good job of getting rid of the 10-micron and smaller particles we know cause the most damage to our health. I recommend the 3M 7500 series respirator masks fitted to your face size.

Is this good enough for a lay person? As long as you have the doors open and the breeze or a good sized fan running you will avoid most of the fine dust buildup. You do need to trade up for a better but more uncomfortable mask. I bought for testing and to try and find more comfort the Trend Air Shield, Triton copy of the Trend, the lightweight 3M and the much more expensive 3M certified PAPR (Powered Air Purifying Respirator) masks. All of these PAPR masks have fans that blow filtered air into what is effectively a face shield with an elastic shroud that fits to your face. The extra air blows out the gaps meaning we always in theory are breathing well filtered air. They are all more comfortable with the new Trend Pro being the best I tried. Most experienced wood turners who work the more toxic woods swear by the Trend Air Shield masks. Unfortunately the lower cost PAPR masks only work ok because their filters are not great, so those of us who are already sensitized really need to buy the more expensive 3M or Trend Air Shield Pro. Believe it or not, only my too expensive 3M PAPR is certified for use around fine dust. My 3M PAPR is certified and I also bought the welding face shield attachment. The cost of one of these high end 3M PAPR masks is so high (unless you find a bargain on eBay or Craigslist) I only recommend them to those who are already suffering with wood allergies or respiratory problems. Or am I a bit light on? Just add a good exhaust fan for the doorway and the better mask.I know I do end up with a reasonable amount of shavings and dust on the floor and benches which I try to clean regularly.(Sorry Major but my shop doesn’t look like yours)

I know there is a lot been said about cyclones and the like but is it feasible or better to run a couple of stages of cyclones before the dusty It's feasible, but you are going to kill your airflow because it takes a lot of work to force air into a tight separation spiral and also with the vac cleaner? I recommend making or buying one of my 6" design cyclones. Your vacuum has plenty of pressure to power a small 6” diameter cyclone and you will find almost nothing goes into the vacuum bin except a little fine dust. With this I mean a coarse dusty then exhausting to a bank of say 3 smaller and then off to a vac cleaner. Or would I be better getting a good hepa filtered vac? I always tell people to buy either a HEPA filter or equivalent for their current vac. Remember that HEPA only means the filter has been individually tested and meets all of the filtering requirements.Or both?

Now with all that said, you really are close to needing a good cyclone separator. When you tire of the filter bag cleanings, your shop filled with sawdust and chips missed by “dusty” and difficulty of emptying your dust collector, a cyclone will be a huge improvement. I personally had to go through all the stages starting with a broom, a cheap DC, a bigger DC, bigger yet DC, then got suckered into a great looking built like a tank cyclone that was a dust pump which filled my closed shop with dangerously unhealthy amounts of dust. I got seriously ill from how much fine invisible dust that expensive purchase I bought to protect my health put into my shop. Learning how poorly that "best" magazine rated cyclone worked made me angry, so I came up with a much better cyclone design that I share for free on my web pages.

Lsst year I worked closely with one of the major U.S. woodworking magazines on their most recent cyclone test. I talked them into also testing for fine dust using a meter. They tested every major U.S. brand of cyclone and a good many of the dust collectors. The results were dismal. Except my cyclone design every other dust collector and cyclone failed because they were dust pumps and only moved about half their advertized airflows in real use. The results were so bad they chose to not print the article. Just too many big advertizers would have been hurt. They did share the results with the other vendors and I am now getting regular complaints because one well known vendor chose to post on their web pages the 6" airflow test results for my 5 hp cyclone design compared to their 5 hp. They kind of forget to tell everone that when my unit was tested with an 8" inlet its airflow tested far better than theirs.

Forgetting the sales pitch for you to build your own cyclone, I do recommend you and most other woodworkers should upgrade to HEPA quality filters on their vacuums and use one of my 6" design cyclones for your vacuum. Our vacuums have plenty of pressure to power a small 6” diameter cyclone and you will find almost nothing goes into the vacuum bin except a little fine dust.

Shane.[/QUOTE]

Originally Posted by bill pentz

Forgetting the sales pitch for you to build your own cyclone, I do recommend you and most other woodworkers should upgrade to HEPA quality filters on their vacuums and use one of my 6" design cyclones for your vacuum. Our vacuums have plenty of pressure to power a small 6” diameter cyclone and you will find almost nothing goes into the vacuum bin except a little fine dust.[/COLOR]

Shane, here is a link to a thread I have started on WIP building a Bill Pentz design mini cyclone. If you decide to build your own.
http://www.woodworkforums.ubeaut.com...ad.php?t=88398

Thanks Bill for the advice and I will have a look at your site and see what I can do in regards to a new cyclone.

Al I had a quick look at your build and it looks quite good. Will have to revisit your build and do one myself I think.

In the meantime I will look at the dust mask you said Bill and invest in a couple of industrial fans to move the air in the shop.

Shane.

Hey Bill, since you are here for the moment - thank you for setting up your site and keeping it going.

Whether people agree with you or not, it has certainly raised awareness amongst woodworkers of the dangers of wood dust and how to manage it. The effort and research must have been considerable (and likely still is).

Guys like you who do their best to provide information to the rest of us deserve more credit than they receive. You've provided a service to woodworkers worldwide for years now, so thanks mate, good on you .

Groggy,

Have to agree with your last post, the service Bill has done for us deserves alot more credit.

I'm one of those woodworkers that had to give up for along time due to poor dust extraction practices in most of the factories I'd worked in.

Starting woodworking again nearly 12 months ago, the only thing I knew about dust was to use a small dust extractor and then basically hope for the best.

This worked well for a few weeks until I worked abit of MDF then bugga me, the old symptoms came back with avengance. That made me find this forum and started me researching about dust.

I found Bill's page which, while not exactly to Bill's specs, led me to building a cyclone, putting in a room filter and using pleated cartridge filter on top of the dusty.

I can now spend a day in the garage doing something I love doing with no apparent ill affects. For that I cant thank Bill, and the rest of you who have added to my knowledge about dust, enough.

If I lived closer I'd like to shake Bill's hand and shout him a bear

After reading all the information on dust, it led me to build a system described in this thread http://www.woodworkforums.ubeaut.com...hlight=cyclone

Anyways, thanks again,

Ross.

Originally Posted by Groggy

Hey Bill, since you are here for the moment - thank you for setting up your site and keeping it going.

Whether people agree with you or not, it has certainly raised awareness amongst woodworkers of the dangers of wood dust and how to manage it. The effort and research must have been considerable (and likely still is).

Guys like you who do their best to provide information to the rest of us deserve more credit than they receive. You've provided a service to woodworkers worldwide for years now, so thanks mate, good on you .

I'll second or fourth that. Thanks for your input Bill.

Cheers
Michael